How to "stick" post on home page of blog.

I am trying to figure out how to "stick" my current post, announcing a writing contest, on the home page of my blog http://pegoleg.wordpress.com/. for at least the next several weeks. I would prefer to have it in the right hand column with the picture there and a "read more" caption so it doesn't obscure my new posts as added. I just changed themes from 2010 to 2011 thinking the Showcase option would work, but can't figure it out. I've read the Theme Showcase info on this theme, checked the forums, and am lost.

If I add a page, can I put a link in the right hand column with a picture? Any help would be GREATLY appreciated.

I think youi will benefit for reading this article on the the Twenty Eleven theme. It's not coded to provide a sidebar on single post pages and nothing you can do will change that reality. The article also clearly describes the Showcase features.

Thank you Timethief. I DID read that article on Twenty Eleven, then I came to the Forums because I didn't understand much of it. Specifically, what part of the sample post was the showcase? The author references section #s, but doesn't show the #s on the examples, which seem to be the Duster theme, not Twenty Eleven.
How do you showcase an existing page or post, or do you have to create a new page? Finally, is there some way to preview changes before you go "live" with them and mess up the blog (as I've already done).